The agency says the increase was the largest since January and resulted mainly from strong gains in Ontario and Alberta.
The combined metropolitan region of Toronto and Oshawa was the top contributor to the August growth, with prices up 0.3 per cent over July.
The largest monthly increase came in Calgary, where prices were up 0.5 per cent in August.
Prices in the combined area of Saint John, Fredericton and Moncton, N.B., fell 0.3 per cent as builders cut prices to spur sales.
Prices were unchanged in seven of the 21 metropolitan areas surveyed.